SU425267A1 - SUBMERSHIP OIL FILLED ELECTRIC MOTORS il 'i - W ^ Shz ^^. Ubi ^ sMj. ^ - Google Patents

Description

one

The invention relates to electrical engineering.

Known submersible oil-filled electric motors containing a stator, ipOTOp with bearings, sealing the upper end of the shaft and the cavity with a reserve of oil in the lower part of the electric motor. However, during the descent into the well, which can last for a long time, a part of the oil can be poured out of the cavity of the electric motor through the open hole, which sharply reduces the reliability of the electric motor.

The purpose of the invention is to improve the reliability of the submersible oil-filled electric motor.

For this purpose, in the cavity of the electric motor, the chamber is filled with air, and at the base of the electric motor there is a springless valve, which serves to communicate the cavity and chamber with the external medium and opening under the pressure of the fluid surrounding the motor. The springless valve is made in the form of a rod with an annular seal located in the cylindrical channel of the base of the electric motor connected by a hole with an air-filled chamber.

The electric motor, in order to enable hermetic separation of the cavity and chamber from each other, contains an overflow

a valve made in the form of a piston with two sealing rings and a thread on the shank, which is placed in the second cylindrical channel of the base of the electric motor, which is connected by holes with the cavity and chamber, the shank being screwed into the threaded hole in the partition between the cylindrical channels. In a cylindrical channel to prevent spontaneous

the valve is closed with an annular groove in which the sealing ring comes in when the valve is opened.

FIG. 1 shows the proposed electric motor, a general view; in fig. 2 - position

valves when the motor is lowered into the well (when the cavity and the chamber are separated from the external environment); in fig. 3 - the position of the valves after the end of the descent into the well (when the cavity and the chamber are interconnected and with the external environment).

The electric motor 1, the driving pump 2, contains a stator 3 and a rotor 4. The internal part of the electric motor is separated from the pump by a seal 5 (rammed, face

or other design). In the lower part of the electric motor there is a cavity A with a reserve supply of oil, inside which there is a chamber 6 with air, limited by a casing 7. At the base of the electric motor

there are cylindrical channels a and b. In one of them there is a springless valve, made in the form of a rod 8 with a seal 9. In the other channel there is an overflow valve 10 with two sealing rings And and 12 and an elongated shank 13 with thread. The valves are sealed with retaining rings 14 and 15. Between the channels there is a threaded hole through which the relief valve stem is screwed. In the upper part of the base, there are vertical holes in, d and e. Depending on the position of the valves, cavity A and chamber 6 can be hermetically sealed from each other and from the environment, and also connected to each other or to the environment. Before filling the motor with oil, the springless valve is shifted by means of the relief valve 10 to the right position, as shown in FIG. 1. Thereafter, the non-relief valve is retracted to the left position, opening the holes connecting the floor and the chamber between them (see Fig. 2).

When filling an electric motor with oil (in the usual way) through openings or valves that are not shown in the drawings, the springless valve will be pressed against the ring 14 by the pressure of the oil column, and hermetically separates the cavity of the electric motor from the surrounding air. Under the action of the same pillar, the air, or other gas in the chamber 6, is compressed, but cannot escape from the chamber, since its casing 7 is sealed. Chamber 6 also serves as a reservoir for additional volume of oil during its temperature expansion during the descent of the electropump into hot wells.

Thus, in the process of mounting and lowering the electric pump, the electric motor remains sealed until it is completely submerged under the liquid level. After the pressure of the surrounding fluid exceeds the pressure of air or gas in chamber 6, the springless valve will move to the left position and open a hole in, informing the lower part of the chamber and the cavity with the liquid. In this case, the seal 9 of the valve without a valve will fall into the annular groove of the channel a, which will exclude the possibility of spontaneous movement of the valve during operation. If the electric pump works in water, the oil from the electric motor cavity does not spill, since its specific gravity is less than the specific gravity of water. In this case, the level of separation of two media is in the lower part of chamber 6, and mixing of these media does not occur, since there are no rotating or moving parts in the chamber. The volume of cavity A of the reserve oil is practically unlimited because there are no pistons, springs, diaphragms or other complex devices. At the same time, oil leakage through the gland seal 5 is insignificant due to the small pressure drop between the upper part of the electric motor cavity and the environment due to the difference in the specific gravities of oil and water (not more than 0.1 atm). In the protector currently used, this pressure drop, created by a special device with a spring and a piston, is 0.5-2 atm. Thus, the motor cavity will be filled with oil, which will ensure the operation of the bearings and winding for a long time.

In the case of an electropump operating in oil, both clean and flooded, its lifespan is not limited at all by the oil supply, since all oil leaks through the seal 5 are compensated by clean oil from cavity A, where

sludge water comes from oil. Oil is known to have sufficiently good lubricating and electrical insulating properties. The operating experience of submersible electric pumps with oil-filled electric motors of the SEM series showed that in all installations that had worked without lifting for 2–5 years or more, the electric motors were filled with oil.

Subject invention

Claims (4)

1. A submersible oil-filled electric motor containing a stator, a rotor with bearings, a seal of the upper end of the shaft and a cavity with a reserve of oil in the lower part of the electric motor, characterized in that, in order to increase reliability, an air-filled cavity is placed in the cavity the chamber, and at the base of the electric motor, there is a springless valve, which serves to communicate the cavity and chamber with the external medium and opens under the pressure of the fluid surrounding the electric motor. 2. An electric motor according to Claim 1, characterized in that the valve is designed as a rod with an annular seal, located in the cylindrical channel of the base of the electric motor, which is connected by an aperture with an air-filled chamber. 3. Electric motor on PP. I and 2, characterized in that, in order to enable hermetic separation of the cavity and chamber from each other during transorting, it contains a non-drain valve made in the form of a piston with two sealing rings and a thread on the shank placed in the second cylindrical channel of the base of the electric motor connected by holes with a cavity and a chamber, the shank being screwed into a threaded hole in the partition between two cylindrical channels. 4. Electric motor on Mon. 1, 2 and 3, characterized in that, in order to prevent spontaneous closing of the valve, an annular groove is made in its cylindrical channel, into which the sealing ring engages when the valve is opened. j ::::: i / I 10 11 72 13 a 9 (pu.1 10 11 12 6 111 a Rig.g 0 11 12 6 T5 9 Ig.E